This invention relates to a far infrared rays radiation device applied to an industrial drying treatment or the like.
A conventional far infrared rays radiation device has structure, as shown in FIG. 6, in which a filament is housed in a glass bulb 1, the filament is electrically supplied from a socket portion 2 connected to an external power source to be heated to a temperature of about 2000.degree. C., and thus far infrared rays reflect from a reflector 3 provided in the glass bulb 1 and radiate to a material to be treated.
However, the far infrared rays radiation device of this type actually radiates infrared rays in a waveband of 0.7 through 3.6 .mu.m. This waveband is different from a waveband of the far infrared rays over 3.6 .mu.m corresponding to a wavelength absorption band of atoms or molecules of materials, and does not correspond to a natural frequency of molecules of materials. Therefore, the above device involves problems that it requires a long time to perform a satisfactory drying treatment and it is not possible to carry out the treatment efficiently. Then, it has been requested to improve efficiency, durability, or mass manufacturing, and to reduce manufacturing cost, at the time when the far infrared rays radiation device has become popular in recent years.